Think about how different sites work before deciding to join a site. Some sites will allow only a defined community of users to access posted content; others allow anyone and everyone to view postings.

Think about keeping some control over the information you post. Consider restricting access to your page to a select group of people, for example, your friends from school, your club, your team, your community groups or your family.

Keep your information to yourself. Don’t post your full name, Social Security number, address, phone number or bank and credit card account numbers – and don’t post other people’s information, either. Be cautious about posting information that could be used to identify you or locate you offline. This could include the name of your school, sports team, clubs and where you work or hang out.

Make sure your screen name doesn’t say too much about you. Don’t use your name, your age or your hometown. Even if you think your screen name makes you anonymous, it doesn’t take a genius to combine clues to figure out who you are and where you can be found.

Post only information that you are comfortable with others seeing – and knowing – about you. Many people can see your page, including your parents, your teachers, the police, the college you might want to apply to next year, or the job you might want to apply for in five years.

Remember that once you post information online, you can’t take it back. Even if you delete the information from a site, older versions exist on other people’s computers.

Consider not posting your photo. It can be altered and broadcast in ways you may not be happy about. If you do post one, ask yourself whether it’s one your mom would display in the living room.

Flirting with strangers online could have serious consequences. Because some people lie about who they really are, you never really know who you’re dealing with.

Be wary if a new online friend wants to meet you in person. Before you decide to meet someone, do your research: Ask whether any of your friends know the person, and see what background you can dig up through online search engines. If you decide to meet them, be smart about it: Meet in a public place, during the day, with friends you trust. Tell an adult or a responsible sibling where you’re going, and when you expect to be back.

Trust your gut if you have suspicions. If you feel threatened by someone or uncomfortable because of something online, tell an adult you trust and report it to the police and the social networking site. You could end up preventing someone else from becoming a victim.

When posting an item for sale on the internet, be aware that that criminals can and do respond to those postings. Never go alone to meet someone to look at an item that you wish to sell or buy. Whenever possible, meet in public at a time and place that you feel safe. Remember when you are speaking and meeting with a potential buyer or seller, that person is a stranger. If you are in a situation that you feel has become unsafe, please do not hesitate to call the police.